cleanup

d2layouts/d2grid/constants.go

@@ -0,0 +1,13 @@
+package d2grid
+
+const (
+	// don't consider layouts with rows longer than targetSize*1.2 or shorter than targetSize/1.2
+	STARTING_THRESHOLD = 1.2
+	// next try layouts with a 25% larger threshold
+	THRESHOLD_STEP_SIZE    = 0.25
+	MIN_THRESHOLD_ATTEMPTS = 1
+	MAX_THRESHOLD_ATTEMPTS = 3
+
+	ATTEMPT_LIMIT = 100_000
+	SKIP_LIMIT    = 10_000_000
+)

d2layouts/d2grid/layout.go

@@ -1,6 +1,7 @@
 package d2grid
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"math"
@@ -479,18 +480,19 @@ func (gd *gridDiagram) getBestLayout(targetSize float64, columns bool) [][]*d2gr
 
 	var bestLayout [][]*d2graph.Object
 	bestDist := math.MaxFloat64
-
+	fastIsBest := false
 	// try fast layout algorithm as a baseline
-	bestLayout = gd.fastLayout(targetSize, nCuts, columns)
-	if bestLayout != nil {
-		dist := getDistToTarget(bestLayout, targetSize, float64(gd.horizontalGap), float64(gd.verticalGap), columns)
+	if fastLayout := gd.fastLayout(targetSize, nCuts, columns); fastLayout != nil {
+		dist := getDistToTarget(fastLayout, targetSize, float64(gd.horizontalGap), float64(gd.verticalGap), columns)
 		if debug {
 			fmt.Printf("fast dist %v dist per row %v\n", dist, dist/(float64(nCuts)+1))
 		}
 		if dist == 0 {
-			return bestLayout
+			return fastLayout
 		}
 		bestDist = dist
+		bestLayout = fastLayout
+		fastIsBest = true
 	}
 
 	var gap float64
@@ -515,22 +517,16 @@ func (gd *gridDiagram) getBestLayout(targetSize float64, columns bool) [][]*d2gr
 	sd := stddev(sizes)
 	if debug {
 		fmt.Printf("sizes (%d): %v\n", len(sizes), sizes)
-		fmt.Printf("std dev: %v\n", sd)
+		fmt.Printf("std dev: %v; targetSize %v\n", sd, targetSize)
 	}
 
 	skipCount := 0
 	count := 0
-	attemptLimit := 100_000
-	skipLimit := 100 * attemptLimit
 	// quickly eliminate bad row groupings
 	startingCache := make(map[int]bool)
-	// try to find a layout with all rows within 1.2*targetSize
-	// skip options with a row that is 1.2*longer or shorter
 	// Note: we want a low threshold to explore good options within attemptLimit,
 	// but the best option may require a few rows that are far from the target size.
-	okThreshold := 1.2
-	// if we don't find a layout try 25% larger threshold
-	thresholdStep := 0.25
+	okThreshold := STARTING_THRESHOLD
 	rowOk := func(row []*d2graph.Object, starting bool) (ok bool) {
 		if starting {
 			// we can cache results from starting positions since they repeat and don't change
@@ -553,7 +549,7 @@ func (gd *gridDiagram) getBestLayout(targetSize float64, columns bool) [][]*d2gr
 			// if multiple nodes are too big, it isn't ok. but a single node can't shrink so only check here
 			if rowSize > okThreshold*targetSize {
 				skipCount++
-				if skipCount >= skipLimit {
+				if skipCount >= SKIP_LIMIT {
 					// there may even be too many to skip
 					return true
 				}
@@ -563,7 +559,7 @@ func (gd *gridDiagram) getBestLayout(targetSize float64, columns bool) [][]*d2gr
 		// row is too small to be good overall
 		if rowSize < targetSize/okThreshold {
 			skipCount++
-			if skipCount >= skipLimit {
+			if skipCount >= SKIP_LIMIT {
 				return true
 			}
 			return false
@@ -586,19 +582,29 @@ func (gd *gridDiagram) getBestLayout(targetSize float64, columns bool) [][]*d2gr
 		if dist < bestDist {
 			bestLayout = layout
 			bestDist = dist
+			fastIsBest = false
+		} else if fastIsBest && dist == bestDist {
+			// prefer ordered search solution to fast layout solution
+			bestLayout = layout
+			fastIsBest = false
 		}
 		count++
 		// with few objects we can try all options to get best result but this won't scale, so only try up to 100k options
-		return count >= attemptLimit || skipCount >= skipLimit
+		return count >= ATTEMPT_LIMIT || skipCount >= SKIP_LIMIT
 	}
 
 	// try number of different okThresholds depending on std deviation of sizes
-	thresholds := int(math.Min(math.Max(1, math.Ceil(sd)), 3))
-	for i := 0; i < thresholds || bestLayout == nil; i++ {
+	thresholdAttempts := int(math.Ceil(sd))
+	if thresholdAttempts < MIN_THRESHOLD_ATTEMPTS {
+		thresholdAttempts = MIN_THRESHOLD_ATTEMPTS
+	} else if thresholdAttempts > MAX_THRESHOLD_ATTEMPTS {
+		thresholdAttempts = MAX_THRESHOLD_ATTEMPTS
+	}
+	for i := 0; i < thresholdAttempts || bestLayout == nil; i++ {
 		count = 0.
 		skipCount = 0.
 		iterDivisions(gd.objects, nCuts, tryDivision, rowOk)
-		okThreshold += thresholdStep
+		okThreshold += THRESHOLD_STEP_SIZE
 		if debug {
 			fmt.Printf("count %d, skip count %d, bestDist %v increasing ok threshold to %v\n", count, skipCount, bestDist, okThreshold)
 		}
@@ -607,17 +613,14 @@ func (gd *gridDiagram) getBestLayout(targetSize float64, columns bool) [][]*d2gr
 			// threshold isn't skipping anything so increasing it won't help
 			break
 		}
+		// okThreshold isn't high enough yet, we skipped every option so don't count it
+		if count == 0 && thresholdAttempts < MAX_THRESHOLD_ATTEMPTS {
+			thresholdAttempts++
+		}
 	}
 
 	if debug {
-		i := 0
-		fmt.Printf("best layout: [\n")
-		for _, r := range bestLayout {
-			vals := sizes[i : i+len(r)]
-			fmt.Printf("%v \t=%v\n", vals, sum(vals))
-			i += len(r)
-		}
-		fmt.Printf("]\n")
+		fmt.Printf("best layout: %v\n", layoutString(bestLayout, sizes))
 	}
 	return bestLayout
 }
@@ -695,6 +698,19 @@ func (gd *gridDiagram) fastLayout(targetSize float64, nCuts int, columns bool) (
 	return layout
 }
 
+func layoutString(layout [][]*d2graph.Object, sizes []float64) string {
+	buf := &bytes.Buffer{}
+	i := 0
+	fmt.Fprintf(buf, "[\n")
+	for _, r := range layout {
+		vals := sizes[i : i+len(r)]
+		fmt.Fprintf(buf, "%v:\t%v\n", sum(vals), vals)
+		i += len(r)
+	}
+	fmt.Fprintf(buf, "]\n")
+	return buf.String()
+}
+
 // process current division, return true to stop iterating
 type iterDivision func(division []int) (done bool)
 type checkCut func(objects []*d2graph.Object, starting bool) (ok bool)